Hydraulic power control valve



2 Sheets-sheet I1 Filed May 13, 1940 .lill/ll i INVENTOR BY E ` ATToR NEY June 10,y 1941. E. A. RocKwELL HYDRAULIC POWER CONTROL VALVE Filed May 13, 1940 2 Sheets-Sheet 2 d m2; mfc. $232.3. :2x3 m55,

Patented Junel 10, v194i HYDRAULIC rownn ooN'raoL vatvn 'Edward Rockwell, West Hartford, Gunn., as-

signor yto The New Britain Machine Co., New. Britain, Conn., a corporation of Connecticut Application Mayv 13, 1940, Aserial, No. 334,103 49c1a1n1s. (c1. aos-54) -My invention relatesfparticularly to a. valve designed for controlling the application of hy- 'draulic power for the operation of any desired apparatus by said power but has particular application to the control of accessories in automotive constructions, as, for example, airplanes, auto mobiles, etc. Y n

The object of my invention is to`provide a valve by means of which more eiective and better con` trolled application of hydraulic power by hy- Fig. is -a plan view o f the lever bracket onthe valve;y

Fig. 6 is a diagram showing the curve of operation of the valve made in accordance with my invention as compared with the curves yobtained generally by previous constructions, b ased on vbrake pressures applied by the valve as compared with the time element of applyingfthe pressure:

. draulic valves can be obtained. .'Hitherl'fb. @Specially in airplane reduction valves, the valves I used for controlling the application of hydraulic pressures for the operation of brakes, both on airplanes as well as automobiles, have been of such a character that 'agreater time element was involved lin theapplication of low hydraulic pressures from a pressure source than in the case of .high pressures therefrom. This time differential has resulted in very uncertain control, especially in the case of airplanes, as it was not possible for 'l the pilot -toapply uniformly the intended braking pressures. One object of my invention is, there fore, to provide substantially the saine time in terval of the application of low pressures'as in the. case of high pressures from said power source.

This construction, furthermore, pr vents the sudden accidental application of the h pressures in the case where quick operation is desired but only low pressures are intended to be applied to the part'tofbe moved. Furthermore, the valve made in accordance with my invention enables' a greater nicety of control to be obtained, especially in the lower range of pressures, as the curve of pressures applied to the part tobe moved does y not mount too suddenly in the distance of pedal travel in the lowerpressurerange and', in fact,

the pedal travel cannot proceed faster than the increase inthe pressures actuallyv applied to the brake, etc. Still'another object is toprovide a construction with which the pilot can feel when the brakes are in, also the service range and the emergency range of ,the pressure applied. Further objects of my invention will appear in the detailed description of the same hereinafter.

While my invention is capable of embodiment in many different forms, by way of illustration I have shown only certain forms thereof in the accompanying drawings in which- Fig. 1 is a vertical section of a valvemade in accordance with my invention;

Fig. 2 is a side elevation thereof;

Fig. 3 is another side'elevation thereof partly in section;

Figui. is a plan view thereof;

brackets 3, I, 5 and 8 thereon for attaching it atl 15g. 7 is a diagram showing the preferred'curves of the brake' pressures applied by my Ivalves as compared with the pedal travel and valve lever travel in the two forms of my invention, in the drawings?v f Fig. 8 is an elevation of a spring stop mechanism which may be used with the mechanism shown in Figs. l to 5, so as to give a feel`when the brakes are set and a feel and the end of. the service range where theemergency rangebegins, as Ashown in one of the curves in Fig. '1; and j Fig. 9 is an `elevation of la brake control with" which the valve can beused.

In the drawings, I have shown a valve casing I having alternative inlets 2 for a `high pressure hydraulic liquid, which delivers to the valve a -pressure, for example of 250' pounds persquare inch or more, or any other desired pressure, from any suitable source of liquid pressure, as' for example the source of liquid pressure as shown 'in my application upon Electro ilow power supply systems, Ser. No. 28,699, filed YJune 27, 1935, Patent No. 2,136,638, granted November 15, 1938, as wellas inthe division thereof, upon Valve and booster. system, Ser. No. 234,637. led October12. 193. The valve casing I has any desired type of anydesired point on the automotive vehicle, as for example an airplane. Also, the said valve casing I has an outlet port I for delivering modv ulatedpressure fromthe valve to any desired part to .be moved thereby, as for example the brakes 'of an airplane. Furthermore, the. said casing I has a return outlet 0 for the liquid dis- A charged from the valve, and which returns to the pressure 'source or any other desired lpoint, as for example in my application aforesaid. Supported from the lower end of the casing I thereis a bracket 9 having four depending screws I0 -provided at' the lower lportion thereof with a springd retainer plate II held-in positioirby nuts. I2 and I3 so as to support a strong coil spring Il, which is selected to suit the particular brakes but which vmay be, for .example a spring requiring 600. pounds to deflect it the upper'end of the spring I4 being arranged to rest against a cen-f trally depressed disk l5. 'I'he leit'end o! to act as the pivotal support for alever i8 which is. U-shaped in creas-sectionv and which has on its under-surface a wear-plate 28 for cooperating Awith an upper curved cam surface 2| adjacent to a downwardly directed surface to clear the leverA I9, cna lever 22 pivotally supported by a pin 28 carried in .earsv24 and 25 on the bracket 8. Thecam surface 2| is diagrammed so aste prol:casaccio th; bracket 8 has an arm I8 provided with a pivotal support l'i `having an opening carrying\a pin I8 going. to the discharge port 8. This end of the cylindrical valve member has a chamfered edge 58 providing a narrow annular valve seat` 54 on which there is adapted to seat a reciprocable valve member 55 havinga central recess 58 in which the upper end ofthe stem 84 is adapted to ilt. This cylindrical valve 5| is arranged to move upwardly and downwardly within a series vide ashifting point of contact between the cam to be resisted by but exert less resisting force than the spring 4, and which carries a pivotal connection 28 with any desired operating link 28 -which may be operated manually or otherwise, as v desired, for the control of the valve mechanism,

so as to control the delivery of the hydraulic liquid under pressure to the part `to be moved, as, for example, -the brakes. o The'leverv 2'| extends within the `Ushaped lever I8, 4and its inner end has a cylindrical recess 38 in which there is carried a wear-button 3| provided with a stem 82 passing through the lever 21. 'I'his wear-button 3| rests beneath a reduced end 88 of a stem 84 having a disk` near the upper 'end thereof.

head 36 which is arranged to reciprocate inthe valve casing Recesses 31 are provided in the .under-,surface of the hea-d 38 to receive the up- .per ends oi' a U-shaped thrust member 38, the

lower portion of which passes beneath the vlever IB'so as to receive abutton 88 in apocket in the end of the rlever 22 extending into a recess and a pin 38a having a similar button 48 positioned in a centrally located depression 4| in the disk I5. This arrangement is -provided in order that as soon as power is applied to the brakes there will be a downward thrust from the head 85 on the Y U-shaped member 38 so as to compress the spring I4 in order to control the travel of the y manually operated link 29.- The' plunger head 88 is screw-threaded into a valve plunger 42, slidc ably carried within the valve cing I. On the peripheryof the plunger 42 thereis an annular inlet chamber 43 communicating with the inlet p'ort 2 for high' pressure liquid, said chamber being sealed at its ends -by annular seals 44 and o! sealed elements. Thesecomprlse an annular spacing member 51 having a discharge port 58 communicating with the discharge port 48. Adjacent thereto there is an annular-rubber seal 58, adjacent to which there is an annular valve member 88 having a conical valve seat 8| cooperating. with a similar valvesurface 82 on the cylindrical valve 5|. The area and diameter of the valve seat 8| andthe valve surface 82 are slightly larger ber seal 81 and adjacent to this there is a spacing member 88 having ports 88. This spacing member 88, at its upper end, rests against a screw plug 'I8 in the plunger 42 which has vertical ports 1| leading to an annular recess.' |2 in the upper face oi' the screw plug lll. The ports 'Il serve to convey the modulated high pressure liquid to the ports 'I and'thence to the brakes. This screw plug 'I8 also serves as a support for one end of an in rnal spring 18 the lower end of which rests against the valve member to normally keep the same off its seat 54. Furthermore, outside of said spring 13 the screw plug 1| has a shoulder 14 to support the upper end of an outer spring 15, the lower end of which rests against an internal shoulder 18 within the cylindrical valve member 5|, the purpose of which is to normally keep the inlet valve 5|, 82 closed. Said cylindrical valve member 5|, furthermore, has a number of radial ports communicating with an annular recess i8 so as to conduct the liquid received through the inlet valve 8|, 82 to.

port 'I to the brakes. When thus being applied to the brakes, the pressure :from the body of oil -ls appliedrincidentally to the upper end oi' thel cylindrical valve 5| having a diameter and area somewhat larger than the diameter and area of the inlet valve 8|, 82 and also exerts a pressure downwardly on the plunger 42, thus causing the pressures supplied to the brakes to act simultaneously downwardly through the U-shaped member 88 to compress the spring |4.

45, and. aA plurality of inlet openings 4'8 give access for the high pressure liquid to the valve mechanism. After ypassing through the valve mechanism the high pressure liquid admitted by the latter is received in a chamber 41 at the upper end oi.' the yalve casing l and ls thence delivered by the port to the brakes .or other accessories to be operated. The eilluent or discharge liquid .passes out of the valve mechanism by ports 48 to an annular chamber 48 in the plunger 42 peripherally sealed by a seal 55 and thence through the discharge port 8. In order to control the course of the hydraulic liquid in this way there is aA cylindrical valve member 5| provided with a longitudinal .passageway 52 passing through the same, the lower end of which acts The mechanism constructed'as above will give, by'means oi' the cam surface 2|, a curve such as the curve I8 shown in Fig.4 7. The diagram in Fig. 7 shows this curve as plotted against brake pressures per square inch, as shown in the ordihates, and the travel of the manual movable parts in the abscissas, the upper set of figures in the latter indicating thejfoot' pedalr travel and the lower set of figures indicating the travel of the pivot 28 of the valve lever 21. In other words,

as a discharge opening for the released iyliqllid .75

in the valves constructed as above the foot pedal travel and the valve lever travel are at all times coordinate to the increase oi' brake pressures applied to the brakes. owing particularly to the spring |4 and the cam surface 2|. Accordingly, it is not possible, as in previous reduction valves to lose eectivc control ot the parts to be move..

L with a perforated plate by suddenly moving the manual means beyond any coordinate application of pressure applied to the brakes. Furthermore, as a corollary thereto,

. vwith this mechanism it is not possible to produce the airplane. The lowerend of the plate |01 is connected `by a pivot. I I3 to a rod ||4 which is screw-threaded so as to receive nuts |I5 and ||8 on the opposite sides of a bracket I I1 fastened ih any suitable way to the airplane. By this means the elevation of the plate |01 can b'e adjusted so as to locate the upper and lower ends-of the slot |05at any desired point, inasmuch as these slots form. stops for thelimits of movement of the pedals 88. The lever |03 is carried on a pivot II8 in an angle bracket ||8 secured to a structural inch and therewith .elapsed time Intervals in seconds from. the time of application of manual force. Instead of these curves 80 to 88, yin the applicants structure on the contrary, the said diagram shows curves 81, 88, 88, 88 and 8| made from .the actual test of one of the applicants controlv valves described as above, showing that-nt does not require a longer time interval to obtain a desired low'pressure level on the brakes, but

' that, on the contrary, in the time interval hith' erto desired for obtaining a high pressure level any lower pressure level on the brakes can be obtained `lwithin this same time interval.

4In Fig. 8 I have shown an elevation of the apparatus which may be used, if desired, comprising an extension 8Ia from the pivot 28 on the bracket 8 having twol pockets 82 and 83 for re'- ceiving coil springs 84 and 88, respectively, which help to determine the curve shown in Fig. '1, carried within and covered by hollow plungers 86 and 81, respectively. The-spring plunger 88 is spaced slightly from the outer right-handend of the lever 21 sovthat the plunger 88 will be contacted by said lever 'at the end of the point where the brakes have been moved into snug position `prior to the service range of brake movement. In

other words, when the brakes are set, the contact of the lever 21 with the plunger 88 will producev a feel on the foot of the pilot to show that the braking force is beginning to be applied in the braking action. At the end of the service range the leve;` 21 then contacts with the sprinsr plunger 81, which gives a .feel to the foot o! the pilot, indicating this position of the parts, but this permits the further application of braking force .through an emergencyrange of pressures by depressing the plunger 81. This is shown on the diagram in Fig. '1, by the curve 88.

In Fig. 9 I have shown the usual means for applying the valve operating mechanism for the operation of the brakes which are attached to the 'usual rudder control of an airplane. As shown therein, there are provided oneof the usual type of pedals 88, two of whichare on the .rudder-bar of the' airplane.. mounted on a pivot |00 on the usual rudder-bar |02 which/ at its lower en d is pivoted to a lever N |03 by means of a pin |04.

Vjects laterally into a curved slot |05 having an Accordingly, the pedal 88 is ,n

, and is connected bya pivoted yoke |8I to alink upward turn- |08 at its lower end, located in.a

plate |01 normally moved to the left ,by a spring |88 attached to some part of the airplane, a wire |08 and a hand-operated knob I8 being located on the other side of said plate |81. Ihes'pring |08 keps the. plate in such a positionthat 'the pin |84 moves only in the up 'anddown portion part I|8a of the airplane as well as to the valve the lever |03 is pivotally connected by a link |20 tothe link 28 on the lever 21.

In the operation of the control valve as applied, vfor example, to airplane Wheel brakes, as soon as the manually operated link 28 is moved to apply the brakes, the left end ofthe lever 21 moves upwardly initially, followed by a movement against the force of the spring I4 as the latter is compressed by the U-shaped member 38 due to the wear-plate 20 bearing on the cam surface 2|, and the inlet valve 8|, 82 thus is immediately opened as soon as the valve 54, has been closed and the cylindrical valve 5| moved upwardly slightly to unseat the valve 8 I. The high pressure liquid entering the port 2 then escapes past the valve 8|, 82 into the interior of the cylindrical valve 5|` where lthe pressure, after being received by the brakes, is immediately exerted against the end of the plunger 4 2 to exert the resultant thrust through the U-shaped member 38 downwardly so as to compress the spring I4. Any desired pressure may thus be appliedto the brakes according to the extent of travel of the lever 21, but as this travel increases the reaction on the spring |4 increases as the wear-plate 20 is progressively moved over the cam surface 2| towards' the pivot 23, thus decreasing the leverage of the manual eil'ort applied tothe spring I4, that is'to'say decreasing with thetravel of the manual means due to the change of fulcrum on the cam surface 2| and with increasingly greater pressures on the brake, as shown in the curve 18. Any one of such pressures may be maintained by the foot, whereupon the valve 8|, 82 will close. When the pressure on the placing the same under pressure again in any de sired way, after 'which it can be :returned to the inlet port 2 when desired, Due to this leverage arrangement it will thus be seenthat thesfoot, in

applying the manual pressure through the link 28, can only travelat all times coordinately to the extentof pressures applied to the brakes, especially as the spring I4 always requires a V l manual eiort in opposition thereto, thus preventing any sudden forward movement of the manual means' beyond the pressures-.being actually applied to the brakes. Furthermore, as shown-in Fig. 6, this prevents-the' disadvantageous feature of said slot and when it is desired to parkwith the brakesheld in a certain position the pin |84,

, vwhen in its down position, is made to' enter the Vup-turn |08 in the slot by the .knob Ill and the lever |08 will then be held in'its down position by serrations III on the-knob ||8 being engaged I|2 in iixed position on inthe operation of prior reduction valves in which a longer time element was required for producing lower levels of pressures on the brakes. This was a very great disadvantage in .the operation of airplanes, where the speed of landing is high and the time factor during landing is very short, so that if the different time element were present for the 44', vdifferent pressures obtained there was a resultantserious lack of control of the airplane in landing.

nections to be made This is exempliiied in the curves Il to II. In

'my construction, however, s exemplied in curves 81 to 9|, there is no longe time element required for the lower level pressures but the lower pressures can be obtained just as quickly as the higher brake pressures and, in fact, the lower brake pressures are attained in sequential order slightly before the higher brake pressures areattained. This enables an extremely eil'ective'and dependable control to be obtained in the operation of, airplanes, etc., and which, as above stated.' is of the utmost importance, especial/ly as applied to the wheel brakes on airplanes.

This control is madeeven more effective by using the spring stops, as shown in Fig. 8. By this means the brake shoes are operated quickly up to the pointwhere the pilot, due to the "feel produced, knows that they are set in position, that is to @ay up to the point where the lever 21 touches the spring housing 96, as shown in the sharp portion at the left end of the curve 98 in Fig. '7. Further application of the manual force depresses the spring housing 96, thus producing the main Dart of the curve 98 through the service range to be applied to the brakes until the end of said curve is reached, whereupon a feel is again felt on the pilots foot due to the lever 21 contacting with the plunger 91.'v A slight further depression of the lever beyond this point provides an emergency range beyondthe service range, as shown at the right end of the curve 08, which is capable of being used in cases of emergency wherethe brakes are to be fully and strongly applied in a short period of time.

In the apparatus shown/in Fig. 9, the operation is the same except in this instance I have shown the usual pedals 98 for operating the respective brakes of an airplane. When each ofl these ped- Y Whilelhave described my invention above in detail I wish it to be understood that many vchanges may be made therein without departing from the spirit of the same.

I claim:

l. A valve mechanism comprising a source of hydraulicpressure, a valve, the operative positions of which are substantially independent of the degree of the pressures delivered thereby, for controlling the delivery of the fluid pressure from the valve mechanism, manual means for operating said valve, and a device for controlling the delivery of saidhydraulic pressure, having an element requiring the extent of movement of vthe manual means to 'accord approximately with the degree of the pressures delivered by said device. f

2. A valve mechanism comprising a source of hydraulic pressure, a valve for controlling the delivery thereof from the valve mechanism, and a device for limiting vthe delivery of said hydraulic pressure, said valve being adapted to resist the manual means less than the resisting eil'ect of the remainder of the valve mechanism on the delivery of said hydraulic pressure.

3. A valve mechanism comprising a source of hydraulic pressure, a part adapted to be moved by the application of the hydraulic pressure thereto, a valve for controlling the delivery of the hydraulic pressure from the valve mechanism, and a reaction element arranged to receive a reaction position coordinate with the hydraulic pressures delivered .to said part by said valve and fix the position of the manual means in accordance therewith irrespective of the position of said part.

. 4. A valve mechanism comprising a source of hydraulic pressure, a valve for controllingthe als is moved downwardly or upwardly there are limits `of movement due to the location of the pin I within the slot lli. Furthermore, the brakes can lbe fastened, for parkingpurposes, in the on-position by moving the plate N1 to the right by means of the hand-knob i I0 thus fasten ing one o: the notches m m thepia u z'after the pin 4M has Abeenmoved downwardly olmov site to the upturn |06 of the slot |05. Furthermore, the stop positions at the bottom and top of the slot |05 can be adjusted by the nuts Il! and i gressive increase inthe pedal travel results always in a coordinate increase in thebrake pressures applied. the same being accomplished irrespective of whether a low or-liighP pressure is delivery thereof from the 'valve mechanism, manual means for operating said valve, and a spring device for obtaining a travel of the manual means with the increase o! pressures delivered by the valve so that the manual means has less a travel than said device.

5. A valve mechanism comprising a source of hydraulic pressure, a valve for controlling the delivery thereof from the valve mechanism, manual means for operating said valve, and a device movable coordinately tothe movement of the to be appliedtov the brakes. Furthermore, all

of these pressures are applied, both 'by an onmodulation as well as an olf-modulation, in such a way that the pressures on the brakes at any one time are accompanied by a coordinate amount of reaction on the foot so that the operato hasasenseatalltimesoftheamountof pr re which he is applying to the brakes, as

well as the beginning and end of the service range of pressures applied. The valve mechanism may be readily installed as the operating leverage may be swung 'around in 'a horizontal plane with regard to the valve so'as to adapt-the positions of the liquid thereonto the conon the airplane.

manual means for obtaining decreasing increments of travel of the manual means with an uniform increase of pressures delivered by the valve. 6. A valve mechanism comprising a source of hydraulic pressure, a valve for controlling the delivery thereof from the valve mechanism, manual means for operating said valve, and a device movable coordinately to the movement of v the manual means including a spring, for obtaining decreasing increments of travel of the manualmeans with an uniform increase of pressuresdelivered by the valve.

7. A valve mechanism comprising a source of hydraulic pressurefa valve for controlling the delivery thereof from the valve mechanism, manual -means for operating said valve, and a device' for preventing the lapse of a longer time inl terval in applying a lower level 'of pressure from delivery thereof from the valve mechanism, manthe valve than when apply/ing a higher level of pressure therefrom.

8. A valvemechanism comprising a sourceV of hydraulicpressure, a valve for controlling the ual means for operating said valve, and a spring device for preventing thel lapse of `a longer time interval in applying a lower levell of pressure from the valve than when applying a higher level of pressure therefrom.

9. A valve mechanism comprising a source of hydraulic pressure, a valve for controlling the delivery thereof from the valve mechanism, manual means for operating said valve, and a device for enabling substantially even low levels of dlivered pressure to be attained before substantially even high levels thereof are reached.

10. A valve mechanism comprising a source of hydraulic pressure, a valve for controlling the. delivery thereof from the valv mechanism, manual means for operating sai valve, and a spring device for enabling substantially even low levels,

of delivered pressure to be attained before substantially even high levels thereof'are reached.l

11. An actuating device comprising a plunger adapted -to be moved by a fluid under a pressure ldiffering from the atmospheric pressure to apply force-thereby, means associated with the plungerfor exerting an increasing resistance to the plunger as it is moved, and a manually movable valve, having a manual Vcontrolling device adapted to be resisted in fixed relationship by said means coordinately with the movement of the plunger.

l2. An actuating devicecomprising aplunger adapted to be moved by a fluid under a pressure differelng from the atmospheric pressure to apply force thereby, a spring associated with the plunger for exerting an increasing resistance to the plunger as it is moved, land a manually mov-.- able valve, having a manual controlling device adapted to be resisted in fixed relationship by said spring coordinately with the movement of the plunger.

13. An actuating device comprising afplunger adapted to be moved by a fluid under a pressure valve associated with the plunger for controlling Vthe movement of the latter, a manually'operable valve lever for operating said valve, and a member adapted to coordinate the movement of the lever to the resisting means-seas to obtain an increasing resistance tothe advance of the movement of the valve lever.

1'?. An actuating device comprising a plunger adapted to be moved b'y a iiuid under a pressure .diifering from the atmospheric pressure to apply force thereby, a spring associated with the p.unger for exerting an increasing resistance to plunger for `exerting an increasing' resistance to the plunger as it is moved, a manually movable l valve associated with the plunger for controlling the movement-of the latter, a manually operable valve lever for operating said valve, and a member, having a cam surface cooperating with the valve lever, adapted to coordinate the movement of thelever to the resisting means so as to obtain an increasing resistance to. the advance of the movement of the valve lever.

19. An actuating device comprising a plunger adapted to be moved by a fluid under a pressure differing from the atmospheric pressure to apply ,f

force thereby, meam associated with the plunger for exerting an increasing resistance to 'l the plunger as itis moved, and a manually movable valve having a manual controlling device adapted to be connected to and resisted in iixed relationship by said-means 'coordinately with the movement of the plunger. l

14. An actuating device comprising a plunger differing from the atmospheric pressure to apply force thereby, a spring associated with the plunger for exerting an increasing resistance to the plunger as it is moved, a manually movable valve associated with the plunger for controlling the movement of the latter, a manually operated c valve lever for operating said valve, and al mem-v ber, having a cam surface cooperating with the valve lever,.adapted to coordinate the movement of the lever to the resisting spring so as to obtain an increasing resistance'to the advance of adapted to be moved by a fluid under .a pressure diierlng from the atmospheric pressure to apply force thereby, a spring associated with "the plunger for exerting an increasing resistance to the plunger as it is moved, and a manually movable valve having a manual controlling device adapted to be connected tov and resisted in fixed.

relationship by said spring coordinately with the I movement of theplunger.

15. An actuating device comprising a plunger adapted to be moved by a nuid under a pressurediffering from the atmospheric pressure toapnly force thereby, means associated with the plunger for exerting an increasing resistance to the the movement of the valve lever.

20. An actuating device comprising aplunger adapted to be moved by a'. fluid under a pressure differing from the atmospheric pressure to` apply force thereby, means associated with the plunger -for exerting an 'increasing resistance to the plunger as it is moved, and a manually movable valve, resisted by said means, associated with the' plunger for controlling the movement of the latl ter, said valve comprising a -tubular valve member operating within the plunger and having Vinlet i Y plunger as it is moved,la manually movable valve associated with the plunger for controlling the movement of the latter, a manually operable valve lever for operating said valve. and 'a memberJ adapted to coordinate the movement of the lever to the 'resisting means so as to obtain a varying resistance to the advance ment of the valve lever.

16. An actuatingdevice comprising a of the' moveadapted-to be moved by a fluidunder a pressure diifering from the atmospheric plunger 'for exerting an increasing-resistance pressure to' vap-v plyliorce thereby, 'means with to the plungerI als-itl moved, a manually movable' j plunger and having inlet and outlet valve Ivelec '.mentsadapted to deliver the pressure from the 78 valve in amounts modulated according to kthe rean'd outlet valve' elements'adapted to deliver the pressure from the valve in 'amounts modulated according to the reaction of the .manual effort applied to thevalve, n

21.l An actuatingy device comprising a plunger adapted to befmoved bya uid under a pressure diilering from the atmospheric' pressure to apply' force thereby, means associated with the plunger vfor .exerting an lincreasing resistance to the plunger as itis moved, and..v manually movable w'valve, connected-toand resis ed by said'means,

'associated with the plunger for controlling the movement of the latter. said valve comprising 'a tuinxlar -valve l member operating v.within the action on the manual eilort applied to the 22. An actuating device comprising a plunger adapted to be moved by a fluid under a pressure v diiiering from the atmosphex'ic pressure to apply force thereby, means associated with the plunger for exerting an increasing resistance to the plunger as it is moved, a manually movable valve associated with the plunger for' controlling the movement of the latter, a manually operable valve lever for operating said valve, and@ meml0 ber adapted to coordinateithe movement of the lever to the resisting means so as to obtain an increasing resistance to the advance of the movement of the valve lever, said valve comprising a tubular valve member operating within the plunger as it is moved, a manually movable valve associated with the plunger iorl controlling the movementoi the latter, a manually v.operable l valve lever for operating said valve, and a member, having a cam surface cooperating with the valve lever, adapted to coordinate the movement of the leverto the resisting means so as to obtain an increasing resistance tothe advance of the movement oi the valve lever, said valve comprising a tubular valve member operating within the pllmger and/having inlet and outlet valve 35l elements Iadapted to deliver the pressure' from the valve in amounts modulated according to the re'- action on the manual eil'ort applied to the valve.

`24.'An actuating de'vice comprising a vplunger differing from the atmmheric pressure to apply force thereby, a springassociated with the plunger for exerting an increasing resistance to valve.

tubular valve located the plunger tor cons trolling the movement oi' the latter, a manually operated valve leverior operating saidvalve, a member adapted t'o-coordinate the thelevertotheresistingsprlngs'oastoobtain an increasing rce tothe advance oi the movement oi the valve lever, said lever and mem-v ber being located between the valve and the spring, and a reaction ber connectlngvwith the plunger for exerting f against -said'spring.

27. An actuating device comprising a plunger adapted to be moved by a iluid under a pressure diii'ering 4from th atmospheric pressure to-apply iorce tnereby, a spring associated with the plunger for exerting an incr resistance to the plunger as it is moved, a manually movable tubular valve located within the plunger for controlling the movement of the latter, a manually voperated valve lever for operating said valve, a member having a cam surface cooperating with the valve lever. 'adapted to coordinate the movement of the lever to the resisting spring so as to obtain an increasing resistance to the advance in the movement of the valve lever, said lever and member being located between the valve and the c spring, and a reaction member connecting with the plunger forexertlng i'o'rce against said spring.

28. An actuating device comprising a plunger adapted to be moved by a fluid under a'pessure diii'ering from the atmospheric pressure to apply force thereby, a spring associated with the plunger for exerting an increasing resistance to the plunger as it is moved, a manually movable adapted to be moved by a nuid under a pressure 40;

the plunger' as it is moved, amanually movable operated valve lever for operating said valve. and' a member adapted' to coordinate the movement 'of the lever to the resistingspring so as to obtain anincreasing resistance to the advance of the movement of the valve lever, said lever and memberl being located between the valve and. the

spring.

25. An actuating device comprising a plungerf tubular valve located within the plunger for ecn'- 45 trolling the movement oi' the latter, a manually tubular valve located within the plunger ior controlling the movement of the latter, a manually operated valve lever for operating said valve, a member adapted to coordinate the movement oftheflever to the resisting spring so asn' to obtain an increasing resistance to the advance of the movement of the valve lever; said lever and member being located between the valve and the spring, and a reaction member-'connecting withthe plunger for' exerting force against said.

spring, said ili'st-mentio'ned memberb'eing'loy cated between the reaction spring- 29. An actuating device comprising s plunger adapted to be moved by a fluid under a pressure Jmember. andsaid differing from the atmospheric pressure to apply v torce thereby, a lspring associated with the plunger for exerting an increasing resistance to v the plunger as it ismoved. a manually` movable tubularf' valve located within the plunger for controlling the movement of the latter, a man' movement o! V adapted to be moved by a iiuid under a pressure dinering from vthe atmospheric pressure to apply .torce thereby, a spring associated with the' plunger tor exerting an increasing resistance to the plunger as it is moved, a manually movable tubular v ve located within the plunger for con.. 60

trolling t e movement-of the latter, a manually operated valve 'lever for operating said valve, and

' a member, having a c am surface cooperating with the valve-lever, adapted to coordinate` the move ment o! the lever to the resisting spring soas to obtain en increasing resistanceto the advance of the movement o! the valve lever, said lever and member being located between the valve and-the 1 Spring- 26. An actuating device comprising a plunger 70 adapted to be moved byu ii'uid under a pressure diiiering from the atmospheric pressure to apply force thereby, a spring Aassociated with thel plunger for exerting an resistance `to the plunger as itis moved, a manually movable uallyoperated valve lever tor operating said valve, a'member. having a cam surface cooperating with the valve lever, adapted to coordinate themovement of the lever in the resisting spring sc as to obtain an increasing to thev advance oi the movement of the valve lever, said lever and member being located between the valve andthe spring, and a reaction member connecting with the plunger for exerting torce against said spring, said mst-mentioned member being located between the reaction member and saidspring.- 80. An'actuating device comprising a plunger,

diilering from the atmospheric pressure to apply torce thereby, means associated with-.the plunger for lexerting an increasing resistance -to the .associated with the plungerfor controlling thadapted to be moved by a iiuid under -a pressure plunger as it is moved, a manually movable valve movement vof the latter. manually movable meansA v to be brought into action when the brakes are lset at the beginning of the service range of power application.

32. An actuating device comprising a plunger adapted ,to be moved by a fluid under a pressure differing from the atmospheric pressure to apply force thereby, means associated with the plunger for exerting an increasing resistance to the plunger as it is moved, a manually movable valve associated with the plunger for controlling the movement of the latter, manually movable means for operating said valve, and a yieldable stop ,associated with said means adapted to be brought \into action at theend of the service range and at the beginning of an emergency range of power application.

33. An actuating device comprising a member adapted to be moved by a fluid under a pressure differing from the atmospheric pressure to apply forcethereby, means associated with the member for exerting an increasing resistance to the mem-- ber as it is moved, and a manually movable valve, having a manual controlling device located so as to be resisted by said means coordinately with the movement of the member.

34. An actuating device comprising a member adapted to be moved by a fluid under a pressure differing from the atmospheric pressure to apply force thereby, a spring associated with the member for exerting an increasing resistance to the member as it is moved, and a manually movable valve, having a manual controlling device located so as to be resisted by said spring coordinately with the movement of the member.

35. An actuating device rcomprising a member adapted to be moved by a iiuid under a pressure differing from the atmospheric pressure to apply force thereby, means associated with the member for exerting an increasing resistance to the member as it is moved, and a manually movable valve, having a manual controlling device located so as to be resisted by said means coordinately with but with less effort than in the movement of the member.

adapted to be moved byl a fluid under a pressure differing from the atmospheric pressure to applyl l force thereby, a spring associated with the member for exerting an increasing resistance to the member as it is moved, and a manually movable valve, having a manual controlling device located so as to be resisted by said spring coordinately with but with less eiort than in the movement of the member.

37. An actuating device comprising a member adapted to be moved by a fluid under a pressure differing from the atmospheric pressure to apply force thereby, means associated with the member for exerting an increasing resistance to the member as it is moved, a manually movable valve associated with the member for controlling the movement of the latter, a manually operable valve lever for operating said valve, a lever to which it is pivoted, and an arm having a cam surface cooperating with the valve lever and inclined at its end to clear the lever pivoted to the valve lever, adapted to coordinate the movement of the lever to the resisting means so as to obtain an increasing resistance tothe advance of the movement of the valve lever.

38. An actuating device comprising a plunger adaptedto be moved by afluid under apressure diering from the atmospheric pressure to apply force thereby, means associated with the plunger for exerting an increasing resistance to the A plunger as it is moved, a manually movable valve.

a valve casing therefor having inlet and outlet ports extending crosswise` to the path of said valve, and valve operating leverage connected to said casing by means permitting different lradial positions of attachment thereto.

39. An actuating device comprising a plunger adapted to be moved by a iiuid under a pressure differing from the atmospheric pressure to apply force thereby, means associated with the plunger for exerting an increasing resistance to the plunger as it is moved, and a manually movable valve reciprocable in said plunger, said plunger .having an inlet port yfor said liquid and having a sealed end provided with a liquid discharge port.

40. An actuating device comprising a plunger adapted to be moved by a fluid under a pressure differing from the atmospheric pressure to apply 36. An actuating device comprising a member force thereby, means associated with the plunger for exerting an increasing resistance to the plunger as it is moved, a manually movable valve, and a U-shaped connecting member leading from the plunger to the resisting means, the'manual device being located between the U-shaped member and the plunger. l

- EDWARD A'. ROCKWELL. 

